[calcite] branch master updated: [CALCITE-3386] CyclicMetadataException singleton instance causes confusion when debugging (Zuozhi Wang)

[hyuan]

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The following commit(s) were added to refs/heads/master by this push:
     new 3f54108  [CALCITE-3386] CyclicMetadataException singleton instance 
causes confusion when debugging (Zuozhi Wang)
3f54108 is described below

commit 3f54108b7dcd4d2b89fc42faab145e2f82883791
Author: Zuozhi <zuozhi....@alibaba-inc.com>
AuthorDate: Fri Oct 4 14:03:51 2019 -0700

    [CALCITE-3386] CyclicMetadataException singleton instance causes confusion 
when debugging (Zuozhi Wang)
    
    Fix misleading stack trace of Calcite's cyclic meta exception. Previously, a
    singleton instance of CyclicMetadataException is reused. However it will 
lead
    to wrong stack trace.
    See https://stackoverflow.com/questions/15090664
    
    Close #1484
---
 .../org/apache/calcite/rel/metadata/CyclicMetadataException.java  | 8 +-------
 .../apache/calcite/rel/metadata/JaninoRelMetadataProvider.java    | 4 ++--
 .../calcite/rel/metadata/ReflectiveRelMetadataProvider.java       | 2 +-
 3 files changed, 4 insertions(+), 10 deletions(-)

diff --git 
a/core/src/main/java/org/apache/calcite/rel/metadata/CyclicMetadataException.java
 
b/core/src/main/java/org/apache/calcite/rel/metadata/CyclicMetadataException.java
index d4dd249..27f3e06 100644
--- 
a/core/src/main/java/org/apache/calcite/rel/metadata/CyclicMetadataException.java
+++ 
b/core/src/main/java/org/apache/calcite/rel/metadata/CyclicMetadataException.java
@@ -21,15 +21,9 @@ package org.apache.calcite.rel.metadata;
  * computing metadata.
  */
 public class CyclicMetadataException extends RuntimeException {
-  /** Singleton instance. Since this exception is thrown for signaling 
purposes,
-   * rather than on an actual error, re-using a singleton instance saves the
-   * effort of constructing an exception instance. */
-  @SuppressWarnings("ThrowableInstanceNeverThrown")
-  public static final CyclicMetadataException INSTANCE =
-      new CyclicMetadataException();
 
   /** Creates a CyclicMetadataException. */
-  private CyclicMetadataException() {
+  public CyclicMetadataException() {
     super();
   }
 }
diff --git 
a/core/src/main/java/org/apache/calcite/rel/metadata/JaninoRelMetadataProvider.java
 
b/core/src/main/java/org/apache/calcite/rel/metadata/JaninoRelMetadataProvider.java
index 24054bb..c669ba3 100644
--- 
a/core/src/main/java/org/apache/calcite/rel/metadata/JaninoRelMetadataProvider.java
+++ 
b/core/src/main/java/org/apache/calcite/rel/metadata/JaninoRelMetadataProvider.java
@@ -273,9 +273,9 @@ public class JaninoRelMetadataProvider implements 
RelMetadataProvider {
           .append("      if (v == ")
           .append(NullSentinel.class.getName())
           .append(".ACTIVE) {\n")
-          .append("        throw ")
+          .append("        throw new ")
           .append(CyclicMetadataException.class.getName())
-          .append(".INSTANCE;\n")
+          .append("();\n")
           .append("      }\n")
           .append("      if (v == ")
           .append(NullSentinel.class.getName())
diff --git 
a/core/src/main/java/org/apache/calcite/rel/metadata/ReflectiveRelMetadataProvider.java
 
b/core/src/main/java/org/apache/calcite/rel/metadata/ReflectiveRelMetadataProvider.java
index 20185b7..64166f4 100644
--- 
a/core/src/main/java/org/apache/calcite/rel/metadata/ReflectiveRelMetadataProvider.java
+++ 
b/core/src/main/java/org/apache/calcite/rel/metadata/ReflectiveRelMetadataProvider.java
@@ -179,7 +179,7 @@ public class ReflectiveRelMetadataProvider
                   key1 = FlatLists.copyOf(args2);
                 }
                 if (mq.map.put(key1, NullSentinel.INSTANCE) != null) {
-                  throw CyclicMetadataException.INSTANCE;
+                  throw new CyclicMetadataException();
                 }
                 try {
                   return handlerMethod.invoke(target, args1);